year PDO 12-yr low-pass filtered PDO 1854 -1.05164 -999.0 1855 -0.00618 -999.0 1856 0.61100 -999.0 1857 0.72593 -999.0 1858 1.94874 -999.0 1859 -0.82057 -999.0 1860 0.08987 0.03873 1861 -1.03799 -0.04854 1862 -0.28386 -0.04647 1863 0.47892 0.01710 1864 0.69104 0.08716 1865 -0.24948 0.12281 1866 0.23895 0.11163 1867 -0.06845 0.06033 1868 0.36792 -0.01974 1869 -0.14188 -0.11634 1870 -0.28709 -0.21067 1871 -0.34628 -0.27748 1872 -0.78524 -0.29754 1873 -0.50315 -0.27082 1874 0.48063 -0.21939 1875 -0.55085 -0.17201 1876 0.02482 -0.14175 1877 0.40969 -0.12123 1878 -0.99565 -0.08975 1879 0.04371 -0.03064 1880 -0.21073 0.05299 1881 1.10174 0.13799 1882 -0.18590 0.18879 1883 -0.58788 0.17985 1884 2.11070 0.11341 1885 -0.42410 0.02556 1886 -0.93260 -0.03189 1887 -1.14847 -0.03471 1888 1.24036 -0.01291 1889 0.14996 -0.04078 1890 0.38604 -0.18063 1891 0.69567 -0.42946 1892 -2.45768 -0.70693 1893 -0.48603 -0.89507 1894 -2.43350 -0.90970 1895 -1.16029 -0.74136 1896 0.28905 -0.45368 1897 -0.10689 -0.14062 1898 0.40738 0.12351 1899 0.59018 0.30980 1900 0.49976 0.43349 1901 0.14488 0.52889 1902 0.93908 0.62363 1903 0.06936 0.72089 1904 1.55696 0.79520 1905 0.99504 0.80306 1906 0.47759 0.70807 1907 1.51091 0.51087 1908 0.96709 0.26073 1909 -1.78123 0.03659 1910 -0.44533 -0.10248 1911 -0.31544 -0.15974 1912 0.48685 -0.19195 1913 0.51968 -0.25760 1914 -0.52119 -0.36352 1915 -0.65382 -0.46214 1916 -1.83627 -0.50175 1917 -0.84588 -0.47519 1918 1.16395 -0.42730 1919 0.09523 -0.41060 1920 -1.18560 -0.43257 1921 -0.99511 -0.44778 1922 -0.26801 -0.39391 1923 -0.12498 -0.24238 1924 -1.49617 -0.02254 1925 0.94769 0.19737 1926 2.14119 0.35143 1927 0.06139 0.41004 1928 -0.60607 0.38426 1929 0.75393 0.30754 1930 0.63297 0.22300 1931 0.33667 0.18175 1932 -0.36701 0.23067 1933 -1.47208 0.38441 1934 1.64928 0.59867 1935 1.03925 0.78491 1936 2.54698 0.87013 1937 0.65368 0.84713 1938 0.10310 0.77034 1939 -0.67727 0.69448 1940 1.34860 0.62187 1941 2.12464 0.51369 1942 0.49772 0.34536 1943 -0.88463 0.14279 1944 -0.70131 -0.04212 1945 0.15316 -0.18432 1946 -0.53126 -0.30458 1947 0.98293 -0.43842 1948 -1.04899 -0.58951 1949 -1.27616 -0.72050 1950 -1.91184 -0.79315 1951 0.03604 -0.80417 1952 -0.60893 -0.78090 1953 -0.86411 -0.73862 1954 0.18585 -0.65368 1955 -2.47088 -0.49088 1956 -1.25441 -0.25366 1957 2.01559 -0.01286 1958 0.46846 0.13103 1959 1.07471 0.12146 1960 -0.25200 -0.01333 1961 -0.94942 -0.18114 1962 -0.98537 -0.29153 1963 0.28376 -0.30749 1964 -0.96066 -0.24990 1965 0.70135 -0.16773 1966 -0.34573 -0.10431 1967 -0.24062 -0.08269 1968 0.21089 -0.10722 1969 0.40472 -0.16689 1970 -0.75529 -0.23985 1971 -0.76102 -0.29915 1972 0.23703 -0.32413 1973 -1.13320 -0.30619 1974 0.64439 -0.24639 1975 -1.26576 -0.15024 1976 0.68182 -0.02250 1977 -0.18332 0.12738 1978 -0.01116 0.28416 1979 0.95873 0.42780 1980 0.67210 0.54203 1981 0.64305 0.62644 1982 0.43763 0.69210 1983 0.95208 0.74947 1984 0.73528 0.79121 1985 0.49297 0.79092 1986 1.69706 0.72560 1987 1.15902 0.60420 1988 -0.33411 0.47821 1989 0.03018 0.41146 1990 -0.52280 0.43424 1991 0.92732 0.52301 1992 1.25143 0.62129 1993 1.76576 0.67712 1994 -0.81705 0.66147 1995 0.71838 0.55903 1996 0.92122 0.36010 1997 1.97103 0.08014 1998 -1.26602 -0.21846 1999 -2.01108 -0.43866 2000 -0.64892 -0.50822 2001 -1.25801 -0.43506 2002 0.84653 -0.30647 2003 0.52000 -0.23194 2004 0.01247 -0.27135 2005 -0.99829 -0.41194 2006 -0.19987 -0.59822 2007 -1.22946 -0.77897 2008 -1.34655 -0.92518 2009 -0.06329 -1.01219 2010 -1.51420 -1.00175 2011 -2.00381 -0.85078 2012 -1.07927 -0.55285 2013 -0.61358 -999.0 2014 1.70712 -999.0 2015 1.39482 -999.0 2016 0.55236 -999.0 2017 -0.01808 -999.0 2018 0.38126 -999.0